diff mbox series

[v2,3/5] i2c: piix4: Add ACPI support for ASF SMBus device

Message ID 20240904105731.2246235-4-Shyam-sundar.S-k@amd.com
State Changes Requested
Delegated to: Andi Shyti
Headers show
Series Introduce AMD ASF Controller Support to the i2c-piix4 driver | expand

Commit Message

Shyam Sundar S K Sept. 4, 2024, 10:57 a.m. UTC 
The AMD ASF controller is presented to the operating system as an ACPI
device. The piix4 driver can obtain the ASF handle through ACPI to
retrieve information about the ASF controller's attributes, such as the
ASF address space and interrupt number, and to handle ASF interrupts.

Currently, the piix4 driver assumes that a specific port address is
designated for AUX operations. However, with the introduction of ASF, the
same port address may also be used by the ASF controller. Therefore, a
check needs to be added to ensure that if ASF is advertised and enabled in
ACPI, the AUX port is not set up.

Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Co-developed-by: Sanket Goswami <Sanket.Goswami@amd.com>
Signed-off-by: Sanket Goswami <Sanket.Goswami@amd.com>
Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
---
 drivers/i2c/busses/i2c-piix4.c | 166 ++++++++++++++++++++++++++++++++-
 1 file changed, 165 insertions(+), 1 deletion(-)

Comments

Andy Shevchenko Sept. 4, 2024, 2:49 p.m. UTC | #1 
On Wed, Sep 04, 2024 at 04:27:29PM +0530, Shyam Sundar S K wrote:
> The AMD ASF controller is presented to the operating system as an ACPI
> device. The piix4 driver can obtain the ASF handle through ACPI to
> retrieve information about the ASF controller's attributes, such as the
> ASF address space and interrupt number, and to handle ASF interrupts.
> 
> Currently, the piix4 driver assumes that a specific port address is
> designated for AUX operations. However, with the introduction of ASF, the
> same port address may also be used by the ASF controller. Therefore, a
> check needs to be added to ensure that if ASF is advertised and enabled in
> ACPI, the AUX port is not set up.

> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Use --cc parameter when sending, instead of this, or alternatively move this
line...

> Co-developed-by: Sanket Goswami <Sanket.Goswami@amd.com>
> Signed-off-by: Sanket Goswami <Sanket.Goswami@amd.com>
> Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
> ---

...to be somewhere here. It will the same effect for you and me
(in case you use `git send-email`).

>  drivers/i2c/busses/i2c-piix4.c | 166 ++++++++++++++++++++++++++++++++-

...

> +struct sb800_asf_data {
> +	unsigned short addr;
> +	int irq;
> +};


> struct i2c_piix4_adapdata {

>  	struct sb800_mmio_cfg mmio_cfg;
>  	u8 algo_select;
>  	struct i2c_client *slave;
> +	bool is_asf;
> +	struct delayed_work work_buf;
>  };

Side note, always run `pahole` when adding new data structures or modifying
existing ones. It might save memory on the running systems.

...

> +static void sb800_asf_process_slave(struct work_struct *work)
> +{
> +	struct i2c_piix4_adapdata *adapdata = container_of(work, struct i2c_piix4_adapdata,
> +							   work_buf.work);

Better split is

	struct i2c_piix4_adapdata *adapdata =
		container_of(work, struct i2c_piix4_adapdata, work_buf.work);

> +	unsigned short piix4_smba = adapdata->smba;
> +	u8 data[SB800_ASF_BLOCK_MAX_BYTES];
> +	u8 bank, reg, cmd = 0;
> +	u8 len, val = 0;
> +	int i;
> +
> +	/* Read slave status register */
> +	reg = inb_p(ASFSLVSTA);
> +
> +	/* Check if no error bits are set in slave status register */
> +	if (!(reg & SB800_ASF_ERROR_STATUS)) {

Why not use positive conditional? (This will require to swap if/else branches)

> +		/* Read data bank */
> +		reg = inb_p(ASFDATABNKSEL);
> +		bank = (reg & BIT(3)) >> 3;
> +
> +		/* Set read data bank */
> +		if (bank) {
> +			reg = reg | BIT(4);

> +			reg = reg & (~BIT(3));
> +		} else {
> +			reg = reg & (~BIT(4));
> +			reg = reg & (~BIT(2));

In all these three cases the outer parentheses are redundant.

> +		}
> +
> +		/* Read command register */
> +		outb_p(reg, ASFDATABNKSEL);
> +		cmd = inb_p(ASFINDEX);
> +		len = inb_p(ASFDATARWPTR);
> +		for (i = 0; i < len; i++)
> +			data[i] = inb_p(ASFINDEX);
> +
> +		/* Clear data bank status */
> +		if (bank) {
> +			reg = reg | BIT(3);
> +			outb_p(reg, ASFDATABNKSEL);
> +		} else {
> +			reg = reg | BIT(2);
> +			outb_p(reg, ASFDATABNKSEL);
> +		}
> +	} else {
> +		/* Set bank as full */
> +		reg = reg | (BIT(3) | BIT(2));

GENMASK() ?

> +		outb_p(reg, ASFDATABNKSEL);
> +	}
> +
> +	outb_p(0, ASFSETDATARDPTR);
> +	if (!(cmd & BIT(0))) {

	if (cmd & BIT(0))
		return;

?

> +		i2c_slave_event(adapdata->slave, I2C_SLAVE_WRITE_REQUESTED, &val);
> +		for (i = 0; i < len; i++) {
> +			val = data[i];
> +			i2c_slave_event(adapdata->slave, I2C_SLAVE_WRITE_RECEIVED, &val);
> +		}
> +		i2c_slave_event(adapdata->slave, I2C_SLAVE_STOP, &val);
> +	}
> +}

...

> +static irqreturn_t sb800_asf_irq_handler(int irq, void *ptr)
> +{
> +	struct i2c_piix4_adapdata *adapdata = (struct i2c_piix4_adapdata *)ptr;

Unneeded explicit casting.

> +	unsigned short piix4_smba = adapdata->smba;
> +	u8 slave_int = inb_p(ASFSTA);
> +
> +	if ((slave_int & BIT(6))) {

Too many parentheses

> +		/* Slave Interrupt */
> +		outb_p(slave_int | BIT(6), ASFSTA);
> +		schedule_delayed_work(&adapdata->work_buf, HZ);
> +	} else {
> +		/* Master Interrupt */
> +		sb800_asf_update_bits(piix4_smba, SB800_ASF_SLV_INTR, SMBHSTSTS, true);
> +	}
> +
> +	return IRQ_HANDLED;
> +}

...

> +static int sb800_asf_acpi_resource_cb(struct acpi_resource *resource, void *context)
> +{
> +	struct sb800_asf_data *data = context;
> +
> +	switch (resource->type) {
> +	case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
> +		data->irq = resource->data.extended_irq.interrupts[0];
> +		break;
> +	case ACPI_RESOURCE_TYPE_IO:
> +		data->addr = resource->data.io.minimum;
> +		break;
> +	}
> +
> +	return 0;
> +}

Why do you still need this callback? What for?

...

> +static int sb800_asf_add_adap(struct pci_dev *dev)
> +{
> +	struct i2c_piix4_adapdata *adapdata;
> +	struct sb800_asf_data data;
> +	struct acpi_device *adev;
> +	LIST_HEAD(res_list);
> +	acpi_status status;
> +	acpi_handle handle;
> +	int ret;
> +
> +	status = acpi_get_handle(NULL, SB800_ASF_ACPI_PATH, &handle);
> +	if (ACPI_FAILURE(status))
> +		return -ENODEV;
> +
> +	adev = acpi_fetch_acpi_dev(handle);
> +	if (!adev)
> +		return -ENODEV;
> +
> +	ret = acpi_dev_get_resources(adev, &res_list, sb800_asf_acpi_resource_cb, &data);

	..., NULL, NULL):

> +	if (ret < 0) {
> +		dev_err(&dev->dev, "Error getting ASF ACPI resource: %d\n", ret);
> +		return ret;
> +	}

Here iterate over the resources and take the ones you need by their respective
types.

> +	acpi_dev_free_resource_list(&res_list);
> +	ret = piix4_add_adapter(dev, data.addr, SMBUS_ASF, piix4_adapter_count, false, 0,
> +				piix4_main_port_names_sb800[piix4_adapter_count],
> +				&piix4_main_adapters[piix4_adapter_count]);
> +	if (ret) {
> +		dev_err(&dev->dev, "Failed to add ASF adapter: %d\n", ret);
> +		return -ENODEV;
> +	}
> +
> +	adapdata = i2c_get_adapdata(piix4_main_adapters[piix4_adapter_count]);
> +	ret = devm_request_irq(&dev->dev, data.irq, sb800_asf_irq_handler, IRQF_SHARED,
> +			       "sb800_smbus_asf", adapdata);
> +	if (ret) {
> +		dev_err(&dev->dev, "Unable to request irq: %d for use\n", data.irq);
> +		return ret;
> +	}
> +
> +	INIT_DELAYED_WORK(&adapdata->work_buf, sb800_asf_process_slave);
> +	adapdata->is_asf = true;
> +	/* Increment the adapter count by 1 as ASF is added to the list */
> +	piix4_adapter_count += 1;

++ also suffice.

> +	return 1;
> +}
kernel test robot Sept. 5, 2024, 9:28 a.m. UTC | #2 
Hi Shyam,

kernel test robot noticed the following build errors:

[auto build test ERROR on andi-shyti/i2c/i2c-host]
[also build test ERROR on linus/master v6.11-rc6 next-20240904]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Shyam-Sundar-S-K/i2c-piix4-Allow-more-than-two-algo-selection-for-SMBus/20240904-190034
base:   https://git.kernel.org/pub/scm/linux/kernel/git/andi.shyti/linux.git i2c/i2c-host
patch link:    https://lore.kernel.org/r/20240904105731.2246235-4-Shyam-sundar.S-k%40amd.com
patch subject: [PATCH v2 3/5] i2c: piix4: Add ACPI support for ASF SMBus device
config: arm-randconfig-003-20240905 (https://download.01.org/0day-ci/archive/20240905/202409051719.oja4MkJZ-lkp@intel.com/config)
compiler: clang version 20.0.0git (https://github.com/llvm/llvm-project 05f5a91d00b02f4369f46d076411c700755ae041)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240905/202409051719.oja4MkJZ-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202409051719.oja4MkJZ-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from drivers/i2c/busses/i2c-piix4.c:26:
   In file included from include/linux/pci.h:1646:
   In file included from include/linux/dmapool.h:14:
   In file included from include/linux/scatterlist.h:8:
   In file included from include/linux/mm.h:2228:
   include/linux/vmstat.h:517:36: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
     517 |         return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
         |                               ~~~~~~~~~~~ ^ ~~~
>> drivers/i2c/busses/i2c-piix4.c:1318:9: error: call to undeclared function 'acpi_fetch_acpi_dev'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
    1318 |         adev = acpi_fetch_acpi_dev(handle);
         |                ^
   drivers/i2c/busses/i2c-piix4.c:1318:9: note: did you mean 'acpi_match_acpi_device'?
   include/linux/acpi.h:932:44: note: 'acpi_match_acpi_device' declared here
     932 | static inline const struct acpi_device_id *acpi_match_acpi_device(
         |                                            ^
>> drivers/i2c/busses/i2c-piix4.c:1318:7: error: incompatible integer to pointer conversion assigning to 'struct acpi_device *' from 'int' [-Wint-conversion]
    1318 |         adev = acpi_fetch_acpi_dev(handle);
         |              ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/i2c/busses/i2c-piix4.c:1322:8: error: call to undeclared function 'acpi_dev_get_resources'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
    1322 |         ret = acpi_dev_get_resources(adev, &res_list, sb800_asf_acpi_resource_cb, &data);
         |               ^
   drivers/i2c/busses/i2c-piix4.c:1322:8: note: did you mean 'acpi_get_event_resources'?
   include/acpi/acpixf.h:809:9: note: 'acpi_get_event_resources' declared here
     809 |                              acpi_get_event_resources(acpi_handle device_handle,
         |                              ^
   include/acpi/platform/aclinux.h:93:21: note: expanded from macro 'ACPI_EXTERNAL_RETURN_STATUS'
      93 |         static ACPI_INLINE prototype {return(AE_NOT_CONFIGURED);}
         |                            ^
>> drivers/i2c/busses/i2c-piix4.c:1328:2: error: call to undeclared function 'acpi_dev_free_resource_list'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
    1328 |         acpi_dev_free_resource_list(&res_list);
         |         ^
   drivers/i2c/busses/i2c-piix4.c:1328:2: note: did you mean 'pci_free_resource_list'?
   include/linux/pci.h:1496:6: note: 'pci_free_resource_list' declared here
    1496 | void pci_free_resource_list(struct list_head *resources);
         |      ^
   1 warning and 4 errors generated.


vim +/acpi_fetch_acpi_dev +1318 drivers/i2c/busses/i2c-piix4.c

  1303	
  1304	static int sb800_asf_add_adap(struct pci_dev *dev)
  1305	{
  1306		struct i2c_piix4_adapdata *adapdata;
  1307		struct sb800_asf_data data;
  1308		struct acpi_device *adev;
  1309		LIST_HEAD(res_list);
  1310		acpi_status status;
  1311		acpi_handle handle;
  1312		int ret;
  1313	
  1314		status = acpi_get_handle(NULL, SB800_ASF_ACPI_PATH, &handle);
  1315		if (ACPI_FAILURE(status))
  1316			return -ENODEV;
  1317	
> 1318		adev = acpi_fetch_acpi_dev(handle);
  1319		if (!adev)
  1320			return -ENODEV;
  1321	
> 1322		ret = acpi_dev_get_resources(adev, &res_list, sb800_asf_acpi_resource_cb, &data);
  1323		if (ret < 0) {
  1324			dev_err(&dev->dev, "Error getting ASF ACPI resource: %d\n", ret);
  1325			return ret;
  1326		}
  1327	
> 1328		acpi_dev_free_resource_list(&res_list);
  1329		ret = piix4_add_adapter(dev, data.addr, SMBUS_ASF, piix4_adapter_count, false, 0,
  1330					piix4_main_port_names_sb800[piix4_adapter_count],
  1331					&piix4_main_adapters[piix4_adapter_count]);
  1332		if (ret) {
  1333			dev_err(&dev->dev, "Failed to add ASF adapter: %d\n", ret);
  1334			return -ENODEV;
  1335		}
  1336	
  1337		adapdata = i2c_get_adapdata(piix4_main_adapters[piix4_adapter_count]);
  1338		ret = devm_request_irq(&dev->dev, data.irq, sb800_asf_irq_handler, IRQF_SHARED,
  1339				       "sb800_smbus_asf", adapdata);
  1340		if (ret) {
  1341			dev_err(&dev->dev, "Unable to request irq: %d for use\n", data.irq);
  1342			return ret;
  1343		}
  1344	
  1345		INIT_DELAYED_WORK(&adapdata->work_buf, sb800_asf_process_slave);
  1346		adapdata->is_asf = true;
  1347		/* Increment the adapter count by 1 as ASF is added to the list */
  1348		piix4_adapter_count += 1;
  1349		return 1;
  1350	}
  1351
kernel test robot Sept. 5, 2024, 9:39 a.m. UTC | #3 
Hi Shyam,

kernel test robot noticed the following build errors:

[auto build test ERROR on andi-shyti/i2c/i2c-host]
[also build test ERROR on linus/master v6.11-rc6 next-20240904]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Shyam-Sundar-S-K/i2c-piix4-Allow-more-than-two-algo-selection-for-SMBus/20240904-190034
base:   https://git.kernel.org/pub/scm/linux/kernel/git/andi.shyti/linux.git i2c/i2c-host
patch link:    https://lore.kernel.org/r/20240904105731.2246235-4-Shyam-sundar.S-k%40amd.com
patch subject: [PATCH v2 3/5] i2c: piix4: Add ACPI support for ASF SMBus device
config: parisc-allmodconfig (https://download.01.org/0day-ci/archive/20240905/202409051743.1sRmenx6-lkp@intel.com/config)
compiler: hppa-linux-gcc (GCC) 14.1.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240905/202409051743.1sRmenx6-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202409051743.1sRmenx6-lkp@intel.com/

All errors (new ones prefixed by >>):

   drivers/i2c/busses/i2c-piix4.c: In function 'sb800_asf_add_adap':
   drivers/i2c/busses/i2c-piix4.c:1318:16: error: implicit declaration of function 'acpi_fetch_acpi_dev'; did you mean 'acpi_match_acpi_device'? [-Wimplicit-function-declaration]
    1318 |         adev = acpi_fetch_acpi_dev(handle);
         |                ^~~~~~~~~~~~~~~~~~~
         |                acpi_match_acpi_device
>> drivers/i2c/busses/i2c-piix4.c:1318:14: error: assignment to 'struct acpi_device *' from 'int' makes pointer from integer without a cast [-Wint-conversion]
    1318 |         adev = acpi_fetch_acpi_dev(handle);
         |              ^
   drivers/i2c/busses/i2c-piix4.c:1322:15: error: implicit declaration of function 'acpi_dev_get_resources'; did you mean 'acpi_get_event_resources'? [-Wimplicit-function-declaration]
    1322 |         ret = acpi_dev_get_resources(adev, &res_list, sb800_asf_acpi_resource_cb, &data);
         |               ^~~~~~~~~~~~~~~~~~~~~~
         |               acpi_get_event_resources
   drivers/i2c/busses/i2c-piix4.c:1328:9: error: implicit declaration of function 'acpi_dev_free_resource_list'; did you mean 'pci_free_resource_list'? [-Wimplicit-function-declaration]
    1328 |         acpi_dev_free_resource_list(&res_list);
         |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~
         |         pci_free_resource_list


vim +1318 drivers/i2c/busses/i2c-piix4.c

  1303	
  1304	static int sb800_asf_add_adap(struct pci_dev *dev)
  1305	{
  1306		struct i2c_piix4_adapdata *adapdata;
  1307		struct sb800_asf_data data;
  1308		struct acpi_device *adev;
  1309		LIST_HEAD(res_list);
  1310		acpi_status status;
  1311		acpi_handle handle;
  1312		int ret;
  1313	
  1314		status = acpi_get_handle(NULL, SB800_ASF_ACPI_PATH, &handle);
  1315		if (ACPI_FAILURE(status))
  1316			return -ENODEV;
  1317	
> 1318		adev = acpi_fetch_acpi_dev(handle);
  1319		if (!adev)
  1320			return -ENODEV;
  1321	
  1322		ret = acpi_dev_get_resources(adev, &res_list, sb800_asf_acpi_resource_cb, &data);
  1323		if (ret < 0) {
  1324			dev_err(&dev->dev, "Error getting ASF ACPI resource: %d\n", ret);
  1325			return ret;
  1326		}
  1327	
  1328		acpi_dev_free_resource_list(&res_list);
  1329		ret = piix4_add_adapter(dev, data.addr, SMBUS_ASF, piix4_adapter_count, false, 0,
  1330					piix4_main_port_names_sb800[piix4_adapter_count],
  1331					&piix4_main_adapters[piix4_adapter_count]);
  1332		if (ret) {
  1333			dev_err(&dev->dev, "Failed to add ASF adapter: %d\n", ret);
  1334			return -ENODEV;
  1335		}
  1336	
  1337		adapdata = i2c_get_adapdata(piix4_main_adapters[piix4_adapter_count]);
  1338		ret = devm_request_irq(&dev->dev, data.irq, sb800_asf_irq_handler, IRQF_SHARED,
  1339				       "sb800_smbus_asf", adapdata);
  1340		if (ret) {
  1341			dev_err(&dev->dev, "Unable to request irq: %d for use\n", data.irq);
  1342			return ret;
  1343		}
  1344	
  1345		INIT_DELAYED_WORK(&adapdata->work_buf, sb800_asf_process_slave);
  1346		adapdata->is_asf = true;
  1347		/* Increment the adapter count by 1 as ASF is added to the list */
  1348		piix4_adapter_count += 1;
  1349		return 1;
  1350	}
  1351
diff mbox series

Patch

diff --git a/drivers/i2c/busses/i2c-piix4.c b/drivers/i2c/busses/i2c-piix4.c
index 003cb04312cf..3bcf2e8b24e7 100644
--- a/drivers/i2c/busses/i2c-piix4.c
+++ b/drivers/i2c/busses/i2c-piix4.c
@@ -60,9 +60,12 @@ 
 #define SB800_ASF_CLK_EN	17
 
 /* SB800 ASF address offsets */
+#define ASFINDEX		(7 + piix4_smba)
 #define ASFLISADDR		(9 + piix4_smba)
 #define ASFSTA			(0xA + piix4_smba)
 #define ASFSLVSTA		(0xD + piix4_smba)
+#define ASFDATARWPTR		(0x11 + piix4_smba)
+#define ASFSETDATARDPTR		(0x12 + piix4_smba)
 #define ASFDATABNKSEL		(0x13 + piix4_smba)
 #define ASFSLVEN		(0x15 + piix4_smba)
 
@@ -118,6 +121,8 @@ 
 #define SB800_PIIX4_FCH_PM_ADDR			0xFED80300
 #define SB800_PIIX4_FCH_PM_SIZE			8
 #define SB800_ASF_BLOCK_MAX_BYTES		72
+#define SB800_ASF_ERROR_STATUS			0xE
+#define SB800_ASF_ACPI_PATH			"\\_SB.ASFC"
 
 /* insmod parameters */
 
@@ -182,6 +187,11 @@  struct sb800_mmio_cfg {
 	bool use_mmio;
 };
 
+struct sb800_asf_data {
+	unsigned short addr;
+	int irq;
+};
+
 enum piix4_algo {
 	PIIX4_SB800,
 	PIIX4_SMBUS,
@@ -198,6 +208,8 @@  struct i2c_piix4_adapdata {
 	struct sb800_mmio_cfg mmio_cfg;
 	u8 algo_select;
 	struct i2c_client *slave;
+	bool is_asf;
+	struct delayed_work work_buf;
 };
 
 static int piix4_sb800_region_request(struct device *dev,
@@ -906,6 +918,66 @@  static s32 piix4_access_sb800(struct i2c_adapter *adap, u16 addr,
 	return retval;
 }
 
+static void sb800_asf_process_slave(struct work_struct *work)
+{
+	struct i2c_piix4_adapdata *adapdata = container_of(work, struct i2c_piix4_adapdata,
+							   work_buf.work);
+	unsigned short piix4_smba = adapdata->smba;
+	u8 data[SB800_ASF_BLOCK_MAX_BYTES];
+	u8 bank, reg, cmd = 0;
+	u8 len, val = 0;
+	int i;
+
+	/* Read slave status register */
+	reg = inb_p(ASFSLVSTA);
+
+	/* Check if no error bits are set in slave status register */
+	if (!(reg & SB800_ASF_ERROR_STATUS)) {
+		/* Read data bank */
+		reg = inb_p(ASFDATABNKSEL);
+		bank = (reg & BIT(3)) >> 3;
+
+		/* Set read data bank */
+		if (bank) {
+			reg = reg | BIT(4);
+			reg = reg & (~BIT(3));
+		} else {
+			reg = reg & (~BIT(4));
+			reg = reg & (~BIT(2));
+		}
+
+		/* Read command register */
+		outb_p(reg, ASFDATABNKSEL);
+		cmd = inb_p(ASFINDEX);
+		len = inb_p(ASFDATARWPTR);
+		for (i = 0; i < len; i++)
+			data[i] = inb_p(ASFINDEX);
+
+		/* Clear data bank status */
+		if (bank) {
+			reg = reg | BIT(3);
+			outb_p(reg, ASFDATABNKSEL);
+		} else {
+			reg = reg | BIT(2);
+			outb_p(reg, ASFDATABNKSEL);
+		}
+	} else {
+		/* Set bank as full */
+		reg = reg | (BIT(3) | BIT(2));
+		outb_p(reg, ASFDATABNKSEL);
+	}
+
+	outb_p(0, ASFSETDATARDPTR);
+	if (!(cmd & BIT(0))) {
+		i2c_slave_event(adapdata->slave, I2C_SLAVE_WRITE_REQUESTED, &val);
+		for (i = 0; i < len; i++) {
+			val = data[i];
+			i2c_slave_event(adapdata->slave, I2C_SLAVE_WRITE_RECEIVED, &val);
+		}
+		i2c_slave_event(adapdata->slave, I2C_SLAVE_STOP, &val);
+	}
+}
+
 static void sb800_asf_update_bits(unsigned short piix4_smba, u8 bit, unsigned long offset, bool set)
 {
 	unsigned long reg;
@@ -1195,6 +1267,88 @@  static int piix4_add_adapter(struct pci_dev *dev, unsigned short smba,
 	return 0;
 }
 
+static irqreturn_t sb800_asf_irq_handler(int irq, void *ptr)
+{
+	struct i2c_piix4_adapdata *adapdata = (struct i2c_piix4_adapdata *)ptr;
+	unsigned short piix4_smba = adapdata->smba;
+	u8 slave_int = inb_p(ASFSTA);
+
+	if ((slave_int & BIT(6))) {
+		/* Slave Interrupt */
+		outb_p(slave_int | BIT(6), ASFSTA);
+		schedule_delayed_work(&adapdata->work_buf, HZ);
+	} else {
+		/* Master Interrupt */
+		sb800_asf_update_bits(piix4_smba, SB800_ASF_SLV_INTR, SMBHSTSTS, true);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int sb800_asf_acpi_resource_cb(struct acpi_resource *resource, void *context)
+{
+	struct sb800_asf_data *data = context;
+
+	switch (resource->type) {
+	case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
+		data->irq = resource->data.extended_irq.interrupts[0];
+		break;
+	case ACPI_RESOURCE_TYPE_IO:
+		data->addr = resource->data.io.minimum;
+		break;
+	}
+
+	return 0;
+}
+
+static int sb800_asf_add_adap(struct pci_dev *dev)
+{
+	struct i2c_piix4_adapdata *adapdata;
+	struct sb800_asf_data data;
+	struct acpi_device *adev;
+	LIST_HEAD(res_list);
+	acpi_status status;
+	acpi_handle handle;
+	int ret;
+
+	status = acpi_get_handle(NULL, SB800_ASF_ACPI_PATH, &handle);
+	if (ACPI_FAILURE(status))
+		return -ENODEV;
+
+	adev = acpi_fetch_acpi_dev(handle);
+	if (!adev)
+		return -ENODEV;
+
+	ret = acpi_dev_get_resources(adev, &res_list, sb800_asf_acpi_resource_cb, &data);
+	if (ret < 0) {
+		dev_err(&dev->dev, "Error getting ASF ACPI resource: %d\n", ret);
+		return ret;
+	}
+
+	acpi_dev_free_resource_list(&res_list);
+	ret = piix4_add_adapter(dev, data.addr, SMBUS_ASF, piix4_adapter_count, false, 0,
+				piix4_main_port_names_sb800[piix4_adapter_count],
+				&piix4_main_adapters[piix4_adapter_count]);
+	if (ret) {
+		dev_err(&dev->dev, "Failed to add ASF adapter: %d\n", ret);
+		return -ENODEV;
+	}
+
+	adapdata = i2c_get_adapdata(piix4_main_adapters[piix4_adapter_count]);
+	ret = devm_request_irq(&dev->dev, data.irq, sb800_asf_irq_handler, IRQF_SHARED,
+			       "sb800_smbus_asf", adapdata);
+	if (ret) {
+		dev_err(&dev->dev, "Unable to request irq: %d for use\n", data.irq);
+		return ret;
+	}
+
+	INIT_DELAYED_WORK(&adapdata->work_buf, sb800_asf_process_slave);
+	adapdata->is_asf = true;
+	/* Increment the adapter count by 1 as ASF is added to the list */
+	piix4_adapter_count += 1;
+	return 1;
+}
+
 static int piix4_add_adapters_sb800(struct pci_dev *dev, unsigned short smba,
 				    bool notify_imc)
 {
@@ -1243,6 +1397,7 @@  static int piix4_probe(struct pci_dev *dev, const struct pci_device_id *id)
 {
 	int retval;
 	bool is_sb800 = false;
+	bool is_asf = false;
 
 	if ((dev->vendor == PCI_VENDOR_ID_ATI &&
 	     dev->device == PCI_DEVICE_ID_ATI_SBX00_SMBUS &&
@@ -1279,6 +1434,10 @@  static int piix4_probe(struct pci_dev *dev, const struct pci_device_id *id)
 		retval = piix4_add_adapters_sb800(dev, retval, notify_imc);
 		if (retval < 0)
 			return retval;
+
+		/* Check if ASF is enabled in SB800 */
+		if (sb800_asf_add_adap(dev))
+			is_asf = true;
 	} else {
 		retval = piix4_setup(dev, id);
 		if (retval < 0)
@@ -1308,7 +1467,9 @@  static int piix4_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	if (dev->vendor == PCI_VENDOR_ID_AMD &&
 	    (dev->device == PCI_DEVICE_ID_AMD_HUDSON2_SMBUS ||
 	     dev->device == PCI_DEVICE_ID_AMD_KERNCZ_SMBUS)) {
-		retval = piix4_setup_sb800(dev, id, 1);
+		/* Do not setup AUX port if ASF is enabled */
+		if (!is_asf)
+			retval = piix4_setup_sb800(dev, id, 1);
 	}
 
 	if (retval > 0) {
@@ -1326,6 +1487,9 @@  static void piix4_adap_remove(struct i2c_adapter *adap)
 {
 	struct i2c_piix4_adapdata *adapdata = i2c_get_adapdata(adap);
 
+	if (adapdata->is_asf)
+		cancel_delayed_work_sync(&adapdata->work_buf);
+
 	if (adapdata->smba) {
 		i2c_del_adapter(adap);
 		if (adapdata->port == (0 << piix4_port_shift_sb800))